Hydraulic Elevators: Holeless Hydro (Twin Jack)

Holeless Hydro

Twin Jack Holeless Car Type Summary

This design uses 2 jacks, one on each side of the car, positioned between the platform and the hoistway wall.

Single stage jacks are used for low travel, typically on 2-stop cars up to 14 ft. Two stage jacks are used for travel up to 28 to 30 feet (typically 3 to 4 stops).

Advantages

The jacks are located above ground, thereby eliminating the need to drill a jack hole and eliminating the risk of oil contamination. This car type will also accommodate low and high-capacity cars.

Disadvantages

Travel is typically restricted to a 2 -4 stop application. Depending upon the travel, an extended overhead may be required to fit the jacks into the hoistway elevation. The hoistway width requirement may also be a little greater than an in-ground car type, for high-capacity applications.

See chart below:

Low Capacity Standard Dimension & Specification Chart

a drawing of a bathroom with a toilet and a shower

Please contact DEM EE on all for drawings.

CAPACITY (LBS.)	OPENINGS F=FRONT R=REAR	DOOR TYPE AND WIDTH	PLATFORM SIZE: W(C) X D(D)	HOISTWAY DEPTH PLATFORM PLUS	HOISTWAY SIZE: W(A) X D(B)	CLEAR INSIDE W X D	RUNNING CLEARANCE SILL/PLAT	SILL DEPTH REQ’D’
2100	F	1-SP 36"	6'-0" X 5'-1"	9"	7'-4" X 5'-10"	5'-8" X 4'-3"	1"	5"
2100	F&R	1-SP 36"	6'-0" X 5'-8"	12"	7'-4" X 6'-8 1/2"	5'-8" X 4'-4"	1"	5"
2500	F	1-SP 42"	7'-0" X 5'-1"	9"	8'-4" X 5'-10"	6'-8" X 4'-3"	1"	5"
2500	F&R	1-SP 42"	7'-0" X 5'-8"	12"	8'-4" X 6'-8 1/2"	6'-8" X 4'-4"	1"	5"
3000	F	1-SP 42"	7'-0" X 5'-6"	9"	8'-4" X 6'-3"	6'-8" X 4'-8"	1"	5"
3000	F&R	1-SP 42"	7'-0" X 5'-11"	12"	8'-4" X 6'-11 1/2"	6'-8" X 4'-7"	1"	5"
3500	F	1-SP 42"	7'-0" X 6'-3"	9"	8'-4" X 7'	6'-8" X 5'-5"	1"	5"
3500	F&R	1-SP 42"	7'-0" X 6'-9"	12"	8'-4" X 7'-9 1/2"	6'-8" X 5'-5"	1"	5"
3500H	F	2-SP 42"	5'-4" X 8'-4"	11"	6'-8" X 9'-3"	5'-0" X 7'-4"	1"	6½"
3500H	F&R	2-SP 42"	5'-4" X 9'-0"	15"	6'-8" X 10'-3 1/2"	5'-0" X 7'-4"	1"	6½"
4000	F	1-SP 48"	8'-0" X 6'-3"	9"	9'-4" X 7'	7'-8" X 5'-5"	1"	5"
4000	F&R	1-SP 48"	8'-0" X 6'-9"	12"	9'-4" X 7'-9 1/2"	7'-8" X 5'-5"	1"	5"
4000H	F	2-SP 48"	6'-0" X 8'-5"	11"	7'-4" X 9'-3"	5'-8" X 7'-5"	1"	6½"
4000H	F&R	2-SP 48"	6'-0" X 9'-1"	15"	7'-4" X 10'-4 1/2"	5'-8" X 7'-5"	1"	6½"
4500H	F	2-SP 48"	6'-0" X 8'-9"	11"	7'-4" X 9'-7"	5'-8" X 7'-9"	1"	6½"
4500H	F&R	2-SP 48"	6'-0" X 9'-6"	15"	7'-4" X 10'-9 1/2"	5'-8" X 7'-10"	1"	6½"
5000H	F	2-SP 48"	6'-0" X 9'-8"	11"	7'-6" X 10'-7"	5'-8" X 8'-8"	1"	6½"
5000H	F&R	2-SP 48"	6'-0" X 10'-4"	15"	7'-6" X 11'-7 1/2"	5'-8" X 8'-8"	1"	6½"

Overhead Required Quick Calculation

Regardless of what the travel is, the standard minimum overhead required for equipment is 12′-6″. Consult your DEM EE representative if your overhead is less than 12′-6″. For every 1″ of travel over 12′-0″ either the overhead or the pit depth must be increased by a corresponding 1″.

Pit Depth	4’-0”
Piston Bottom Under-travel	9”
Car Speed	Up To 150 FPM
Cab Height	8’-0”
Piston Top Over-travel	5"

Maximum Inside Net Platform Areas

To allow for variations in cab designs, an increase in the maximum inside net platform area not exceeding 5% shall be permitted for the various capacity loads.

Rated Capacity (LBS.)	Inside Net Area (SQ. FT.)
2100	24.2
2500	29.1
3000	33.7
3500	38.0
4000	42.2
4500	46.2
5000	50.0

Approximate Clear Inside Dimensions of CAB

Width = Platform Width less 4”

Depth = Front Open Only

SSSO & CO Doors = Platform Depth Less 10” 2SSO Doors = Platform Depth less 12”

Depth = Front & Rear Open

SSSO & CO Doors = Platform Depth Less 16” 2SSO Doors = Platform Depth less 20”

DBG (Distance Between Guides)
Platform Width plus 3 ¼” 12# / 15# rail depth= 3 ½”

Rail Bracket Fastening to Hoistway Walls

Hoistway wall supports for rail bracket fastenings are required per the layout drawing locations. For block or masonry walls, wall inserts must be installed in the walls by someone other than the elevator contractor. Masonry block must be filled with mortar around wall inserts to provide a solid permanent rail bracket support.

For wood and metal stud hoistway walls, covered with sheetrock, a suitable header support (running front-to-back on each hoistway side wall) is required at each rail bracket location, as per the rail force and location shown on the job specific layout drawing.

Single Stage Jacks

UP to 100 FPM:
Pit Depth = 4’-0”
Overhead = 12’-6”
Top Over Travel = 3.5”
Bottom Over Travel = 5.0”
Max. Travel = 13’-10”
Max. “Overall” Cab Height = 8’-6”

101-125 FPM:
Pit Depth = 4’-0”
Overhead = 12’-6”
Top Over Travel = 4.25”
Bottom Over Travel = 7.25”
Max. Travel = 13’-4”
Max. “Overall” Cab Height = 8’-6”

Two Stage Jacks

UP to 100 FPM:
Pit Depth = 4’-0”
Overhead = 12’-6”
Top Over Travel = 9”
Bottom Over Travel = 7”
Max. Travel = 24’-4”
Max. “Overall” Cab Height = 8’-2”

101-125 FPM:
Pit Depth = 4’-0”
Overhead = 12’-10”
Top Over Travel = 11.0”
Bottom Over Travel = 9.0”
Max. Travel = 24’-4”
Max. “Overall” Cab Height = 8’-2”

Contact DEM Elevating Equipment for required hoistway width for Telescopic or Roped arrangements.

* Consult factory for required hoistway width for telescopic jack application

Hoistway dimensions shown are not for final construction purposes. National & Local code years and variations may affect sizes shown. All dimensions
should be verified with DEM Elevating Equipment prior to construction.